Towel rack



FIG. 1 illustrates a top view of the claimed design for a towel rack;

FIG. 2 illustrates a front view thereof;

FIG. 3 illustrates a left-side view thereof;

FIG. 4 illustrates a right-side view thereof;

FIG. 5 illustrates a rear view thereof;

FIG. 6 illustrates a bottom view thereof;

FIG. 7 illustrates an internal sectional view thereof; and,

FIG. 8 illustrates a perspective view thereof.

The ornamental design for a towel rack, as shown and described.